Your server is running. The service says "Started." But the Diagnoser looks deeper. It checks if the license server is activated with Microsoft. It checks if it has been discovered via AD or Registry. Often, the Diagnoser finds a server that is technically alive but deaf to the Session Host. The fix? Reconfiguring the discovery scope—a five-minute fix that would have taken hours to find manually.
Verifies that the host is pointed to the correct license server. rd licensing diagnoser
Click on Tools in the upper right corner. Your server is running